Until a train is a safe distance from the station, it must travel at 5 m/s. once the train is on open track, it can speed up
to 45 m/s. if it takes a train 8 seconds to reach 45 m/s, what is the acceleration of the train?
m/s4

The acceleration of the train is 5 m/s².

Explanation:

Acceleration is the change in velocity over a given time interval.

Therefore, acceleration is given as:

Where, are initial and final velocities and is the time interval.

Here,

This gives,

Therefore, the acceleration of the train is 5 m/s².

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.